Introduction: The introduction of novel technologies such as nickel-titanium (NiTi) instruments and new canal filling systems have helped the dentist, and reduces the operating time. Objective: To evaluate root canal enlargement following mechanical shaping using 2 nickel-titanium rotary systems. Methods: 60 single-rooted teeth were immersed in resin and sectioned perpendicular to the long axis at 4, 8, and 12 mm from the apex. Digital capture of sections was achieved before and after canal instrumentation using Mtwo and Revo-S instruments. The area upsurge of endodontic space was calculated by subtraction. Results: The use of both instruments has permissible for removal of excessive amounts of dentin from the canal walls, even when the endodontic morphology is characterized by gracelessness to reach recesses. Conclusions: Both procedures appear to be effective and no differences were observed amongst Mtwo and Revo-S allowing for the amount of dentin removed at different distances from the apex.